Acoustic emission characteristics of lamprophyre under uniaxial loading

摘要

As the coal and rock strata of many mining areas are largely permeated by lamprophyre, the coal mining working face emerged abnormal pressure.But the study on lamprophyre is very few at present.In allusion to these problems, the Acoustic Emission (AE) tests of lamprophyre under conventional uniaxial compression loading were carried out by using YAW-1000 electro-hydraulic servo universal testing machine and PCI-2 acoustic emission signal acquisition system, AE characteristics of lamprophyre under uniaxial loading were analyzed with loading time and stress changing, and the evolution of internal crack and the law of development of lamprophyre under external loading were explored by the location technique.The results show that: 1.The failure process of lamprophyre experienced crack-consolidation stage, elastic stage and failure stage after the peak;the plastic stage cannot be found and AE quiet period will not appear.2.AE information occurs in the process of uniaxial loading can reflect the internal failure process of lamprophyre and coincide with the 3 stages of lamprophyre under uniaxial loading;the change trends of energy, count and amplitude with time are similar;AE mutation point which can be used as a precursor to determine the lamprophyre failure is emerged at about 80％ of the peak stress;3.The evolution of cracks from initiation and growth to connectivity of lamprophyre is shown from the microcosmic point through the test on the 3D-distribution of AE signals.